Light fixture for flasher units



March 21, 1967 E. D. NUNN 3,310,671

LIGHT FIXTURE FOR FLASHER UNITS Filed March 4, 1965 3 Sheets-Sheet 1 28 M 39 /ndmw on) .Ewmg ,U. Nunn March 21, 19 7 D, NUNN 3,310,671

LIGHT FIXTURE FOR FLASHER UNITS Filed March 4, 1965 Sheets-Sheet 2 March 21, 1967 D. NUNN 3,310,671

LIGHT FIXTURE FOR FLASHER UNITS Filed March 4, 1965 3 Sheets-Sheet 3 United States Patent 3,310,671 LIGHT FIXTURE FOR FLASHER UNITS Ewing D. Nunn, Mequon, Wis., assignor to Flo-Tronics,

Inc., doing business as Northern Signal Co., Minneapolis, Minn, a corporation of Minnesota Filed Mar. 4, 1965, Ser. No. 437,171 8 Claims. (Cl. 240-111) This invention relates broadly to light fixtures and refers more particularly to outdoor light fixtures suitable for flasher units used as warning signals.

Flashing-type signal lights of this nature are used extensively on construction projects of all types. Hence, they are in constant danger of being struck by passing trucks and earth-moving equipment, and sometimes are intentionally struck by vandals using stones, sticks or anything else that might be handy. Consequently, ruggedness is one of the main requisites of such light fixtures.

In full recognition of this fact, the present invention has as its purpose and object to provide a light fixture for flashing-type signal lights which is so ruggedly constructed as to be capable of being struck with a baseball bat without being damaged.

Another object of this invention is to provide a light fixture for the purpose described, which is characterized by an unprecedented simplicity of construction which makes assembly of the fixture, and particularly the lenses and light source thereof, a very easy matter.

In this connection it is a further object of this invention to provide a light fixture of the character described which is so constructed as to form a weather-tight enclosure which nevertheless can be rotated to orient the same most advantageously upon a supporting wall such as the top panel of a cabinet containing the electrical control system for the flasher unit.

Still another object of this invention is to provide a light fixture which consists essentially of a substantially cylindrical rim or shell'formed of rubber-like, tough, elastic weather-proof material and two lenses which are made of a suitable plastic material and hence practically indestructible; the shell being provided by a length of extruded material rolled into a cylinder and having abutting ends which are interlockingly secured together.

Still another object of this invention is to provide an improved manner of removably mounting a light bulb socket assembly in the fixture.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for "ice FIGURE 3 is a section-a1 view through the rim connector means, taken on the plane of the line 3-3 in FIG- URE l;

FIGURE 4 is an elevational view similar to FIGURE 1,

' showing how the rim forming strip can be rolled into place to provide the shell of the fixture, and having portions broken away and shown in section; 1

FIGURE 5 is a sectional view on the line 5-5 in FIG- URE 1;

FIGURE 6 is a perspective view of the fixture mounting shoe;

FIGURE 7 is a planview of a barricade having light fixture of this invention mounted thereon; and

FIGURE 8 is a perspective view of the lamp socket assembly per se.

Referring now particularly to the accompanying drawings, the numeral 5 indicates generally the more or less drum shaped enclosure or housing of the light fixture of this invention, and which consists of a cylindrical rim or shell 6 and two spaced apart lenses 7 joined at their peripheries to the rim with a weather-tight connection therebetween.

The lenses 7 are molded from a tough nearly transparent plastic material and, if desired, may have reticulated outer surface configurations and Fresnel type lightrefracting concentric ridges on their inner faces. The lenses also have flanged peripheries 8 which are tightly received in the outermost of three equisp-aced annular grooves 9 in the inner surface of the rim 6, so as to provide a weather-proof junction between the lenses and the rim.

The rim or shell 6 comprises a strip of tough, elastic, rubber-like material such as polyvinyl chloride. It is made from a substantially fiat extruded length of plastic material. The extrusion process enables the grooves 9 to be given the desired cross sectional size and shape, and provides an economical and entirely practicable method of forming the shell.

The strip is accurately cut to length to provide beveled end surfaces 10 which mate with one another when the ends are joined, and so that the resulting cylindrical rim or shell will be of the desired diameter.

To hold the strip in place encircling the lenses 7, one end portion of the strip is riveted to a mounting shoe 11, and the other end portion of the strip is riveted to a connecting shoe 12. These shoes are preferably of molded plastic material, and each has an arched plate portion 13 which fits flush against the cylindrical outer surface of the shell. Rivets 14 passing through the arched plate portions 13 and the rim outwardly of the grooves 9 therein securely hold the shoes in place on the portion 13 of the connecting shoe 12 at a location directly adjacent to the joint between the beveled ends 10 of the plastic rim forming strip. This lug has a bore 16 disposed on an axis tangent to a circle somewhat larger in diameter than the rim 6, and which opens to the rear of the lug and away from the joint through a counterbore 17. A screw 18, which projects through the bore 16 in the lug, has its head 19 disposed in the counterbore and its threaded stem 20 projects from the front of the lug. This screw is held captive in the lug as by means of a C-washer 21 engaged in a circumferential groove 22in the stem 20 adjacent to the front of the lug.

A similar lug 23 is formed on the exterior of the plate portion 13 of the mounting shoe 11, at a location directly adjacent to the joint between the beveled ends of the rim strip. This lug has a threaded hole 24 therein to receive the stem 20 of the screw 18, so that tightening the screw draws the lugs toward one another to securely engage the rim around the peripheries of the lenses and bring the ends 10 of the strip into mating engagement. This also brings the opposing faces of the lugs and 23 into contiguous relationship over the joint between the beveled ends 10 of the rim strip, to more or less conceal the joint and prevent access thereto. The hole 24 opens toward the lug 15 through a counterbore 25 which accommodates the C-washer 21.

Greater assurance against tampering with the joint between the beveled ends 10 of the rim strip by vandals and the like is afforded by reason of the provision of tabs 26 on the connecting shoe 12, which flank the boss 15 thereon and in eifect form extensions of its plate portion, but offset outwardly thereof to extend forwardly beyond the front of the lug 15 into closely, overlapping relation with the plate portion 13 of the mounting shoe 11, at both sides of the lug 24 thereon. In addition, the plate portion 13 of the mounting shoe 11 is formed with short extensions that define lips 27 at opposite sides of its lug 24, and which lips extend over the joint between the beveled ends 10 of the rim strip at the exterior thereof. This results in a unique interlocking connection between the ends of the rim strip, providing maximum security against tampering with the joint therebetween.

It should also be observed that the captive screw 18 is of special construction in that it has a post 28 formed on its head 19, in the center of a hexagonal socket 29, to prevent turning the screw by any except a special hexagonal tool having a well to receive the post. This, of course, precludes unauthorized persons for disconnecting the rim from the lenses.

The mounting shoe 11 is adapted for securement to a panel 31 that ordinarily comprises the top wall of a cabinet 32 in which the batteries and electrical control instrumentalities for the flasher unit are housed. These cabinets are usually provided with a door (not shown) a tone side thereof, or with a removable cover, by which access may be had to the interior of the cabinet; and the cabinets are customarily, though not always, mounted on the top cross bar 33 of a barricade 34 in the manner indicated in FIGURE 7.

According to this invention, the mounting shoe 11 is formed with a hollow boss 35 which projects from its arched plate portion 13 at a location directly adjacent to the rear of the lug 23 thereon. This boss has a radial bore 36 therethrough which opens internally toward the rim 6 through an enlarged hexagonal well 37 in the base portion of the boss, and registers with a hole 38 in the rim 6. An externally threaded bushing 39 projects through the bore 36 in the boss and extends a distance beyond its outer end. The head 40 of the bushing is enlarged and of hexagonal shape, and fits in the hexagonal well 37 in the base of the boss to prevent the bushing from rotating relative to the mounting shoe. Preferably, an annular resilient Weather-tight sealing gasket 41 is confined under compression between the rim and the underside of the mounting shoe, where it encircles the mouth of the hole 38 in the rim and extends inwardly over the mouth of the well 37 to engage the head of the bushing therein.

In this way also, the head 40 of the bushing is confined between the rim 6 and the bottom 42 of the well 37 so as to prevent axial movement of the bushing in the boss 35.

The light fixture is usually mounted on the panel or top wall 31 of the cabinet 32 with the shoe 11 thereof lowermost, and with the outer end of its boss abutting the upper surface of the panel and its bushing projecting through a hole 43 therein. A nut 44 threaded onto the bushing and engageable with the underside of the panel can thus draw the boss 35 firmly down onto the panel to securely hold the fiixture in place thereon.

In the present case, the outer end of the boss is spaced from the outer surface of the panel 31 by a pair of washers 45 and 46 which encircle the projecting end of the bushing 39. The lowermost washer 46 is formed of metal and is adapted to be nonrotatably held against the panel 31 by friction. The upper washer 45 is formed of nylon or a similar low friction plastic material, and allows the housing of the fixture to be rotated relative to the lower washer 46, provided that the nut 44 is not too tightly engaged with the underside of the panel.

The washer 46 has a tab 47 bent upwardly from its periphery to lie alongside the exterior of the boss 35. This lug can be engaged between closely spaced abutments 48 on one side of the exterior of the boss 35, as indicated in FIGURE 5, to prevent rotation of the hous ing relative to the panel, and to preferably hold the housing in the solid line position seen in FIGURE 7 where its axis is normal to the top cross bar 33 of a barricade carrying the light fixture. The boss 35 has a second pair of substantially diametrically opposite abutments 49 on its exterior, which are engageable with the tab 47 on the lower washer when the tab is disposed at the opposite side of the boss 35 to allow the flasher housing to be rotated through an angle of about This permits the flasher housing to be adjusted to different positions relative to the barricade, as shown in broken lines in FIGURE 7, or even to be disposed with its axis parallel to the top cross bar 33 of the barricade if desired.

With the washer 46 oriented as shown in the drawings, namely with its tab at the side of the boss 35 remote from the closely spaced abutments 48, the tab limits rotation of the fixture to the extent provided by the diametrically opposite abutments 49, or in other words through an angle of about 180".

It will be understood, of course, that the clamping nut 44 must be temporarily loosened sufficiently to enable the tab on the washer to be disengaged from one pair of cooperating abutments on the boss before it can be oriented for cooperation with the other pair of abutments. Similarly, the clamping nut 44 can be tightened to whatever extent is necessary to hold the adjustment of the fixture at times when the tab is not confined between the closely spaced abutments 48.

The light fixture of this invention also features an exceptionally simple socket assembly 51 for supporting an incandescent bulb 52 at the exact center of the housing entirely without screws, rivets or other fasteners. As here= in shown, the socket assembly 51 comprises an elongated tubular stem 53 of substantially stiff but resilient plastic material, a socket shell 54 mounted in the upper end of the stem to receive the bulb 52, and a pair of conductors 55 fixed to the socket 54 and extending downwardly through the hollow interior of the stem. The socket assembly is carried by the bushing 39, with the lower end portion of the stem 53 axially slidably but frictionally engaged in the bore 56 of the bushing.

A series of circumferentially spaced longitudinally extending embossments 57 formed on the exterior of the lower portion of the stem materially improve the frictional engagement between the stem and the wall ofthe bore in the bushing, and assure against accidental axial displacement of the stem from a predetermined position holding the bulb 52 at the center of the housing. This position of the stem is defined by the engagement of a flange 58 on the bottom of the stem with the lower or outer end of the bushing 39. r

The tubular stem 53 is taperingly reduced in diameter toward its upper end, and both the bulb 52 and its socket 54 are slightly smaller in diameter than the smallest diameter upper end portion of the stem. This, of course, enables the socket assembly to be easily inserted into or removed from the bushing 39 from the interior of a cabinet upon which the fixture is mounted, without eutailing disassembly of any of the components of the housing.

As stated, the flange 58 on the bottom of the stem limits insertion of the socket assembly into the bore of the bushing 39,v and thus defines the axial position of the stem with respect to the axis of the housing. The socket shell 54 is inserted into the upper end of the stern and frictionally held therein. It has the usual bayonet slot 59 which serves to accurately position the bulb in the socket shell. However, in the absence of some means to define the axial position of the socket shell with respect to the stem 53, it would be very difficult to position the bulb with its filament exactly at the center of the housing and its lenses, where it must be located for maximum light output.

According to this invention the desired axial position of the socket shell in the upper end of the stem 53 is defined by a ledge 60 formed integrally with the stem,

and against which the bottom of the socket shell abuts to limit its insertion into the stem. This ledge, of course, is so located as to assure that the bayonet slot 59 will be slightly above the top of the stem for easy insertion of the bulb into the socket. The ledge 60 also has a hole 61 therein through which the socket conductors 55 pass.

It should be observed that the insertion of the socket shell 54 into the upper end of the stem causes the latter to be expanded slightly, to thus assure the degree of friction between these parts necessary to prevent accidental axial displacement of the socket shell from its proper position.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent to those skilled in this art that this invention provides a light fixture which because of its exceptional ruggedness is well suited for use with flashing signals used on street, highway, and construction projects as warning devices; and that in addition to being exceptionally rugged, the fixture of this invention features unusual simplicity of construction and thus may be easily and inexpensively produced.

I claim:

1. A light fixture adapted for mounting on one side of a supporting wall, and of the type comprising a pair of coaxial spaced apart discs, and a cylindrical rim encircling the discs and coacting therewith to provide a drum-shaped enclosure for a light source, at least one of said discs being a lens through which light can pass, said fixture being characterized by the following:

(A) that said rim comprises an annulus of tough weather-proof elastic material, having a radial hole therethrough;

(B) a plastic mounting shoe shaped to conform to the exterior of the rim and secured thereto over said hole;

(C) a boss integral with said shoe and projecting from the exterior thereof, said boss having a bore therethrough coaxial with said hole, and having a noncircular counterbore opening toward the rim;

(D) and a bushing received in said bore, said bushing having a head nonrotatably received in said counterbore and contiguous to the exterior of the rim, and said bushing having an externally threaded end portion extending beyond the outer end of said boss so as to project through a hole in a supporting wall upon which the fixture is mounted for the reception of a nut by which the head of the bushing can be drawn down against the bottom of the counterbore to clamp the boss between said wall and the head of the bushing.

2. The light fixture of claim 1, further characterized by:

(A) a washer encircling said threaded end portion of the bushing and adapted to be nonrotatably clamped between the outer end of said boss and a supporting wall upon which the fixture is mounted;

(B) a lug on the periphery of said washer extending along the exterior of said boss;

(C) and stop abutment means on the exterior of the boss engageable with said lug to limit rotary movement of the fixture about the axis of said boss.

3. The light fixture of claim 2, further characterized by a plastic antifriction washer encircling said threaded end portion of the bushing and confined between said nonrotatable washer and the outer end of the boss to facilitate rotary adjusting movement of the fixture on its support, between limits defined by said lug and stop abutment means.

4. The light fixture of claim 1, further characterized by an annular resilient seal of weather-proof material coaxial with the hole in the rim and confined between the latter and the underside of said shoe, said seal extending over the head of the bushing and extending radially outwardly beyond the mouth of the counterbore to prevent water that may seep into the joint between said shoe and the exterior of the rim from entering either into the mouth of the counterbore or the bore in the head end of the bushing.

5. A light fixture adapted for mounting on one side of a supporting wall, and of the type comprising a pair of coaxial spaced apart discs, and a cylindrical rim encircling the discs and coacting therewith to provide a drum-shaped enclosure containing a light source, at least one of said discs being a lens through which light from the source can pass, said fixture being characterized by the following:

(A) that said rim comprises a strip of tough weatherproof elastic material wrapped around the peripheries of the discs and having interconnected rim securing elements on its opposite ends to hold the same in place on the discs with the ends of the strip in abutting relation, said rim having a radial hole therethrough at one end portion of the strip;

(B) a first plastic shoe shaped to conform to the exterior of the rim and secured to said one end portion thereof over said hole, said shoe extending circumferentially to the adjacent end of the strip and having one of said rim securing elements thereon;

(C) a second plastic shoe shaped to conform to the exterior of the rim and secured to the opposite end portion thereof, said second shoe extending circumferentially to the adjacent end of the strip and having the other of said rim securing elements thereon;

(D) and means on said first shoe for securing the fixture to one side of a supporting wall, including a boss integral with said first shoe and having a bore therethrough in register with said hole in the rim, and a bushing coaxially received in said bore and nonrotatably connected to said shoe, the bushing providing a support for said light source.

6. The light fixture of claim 5, further characterized by the fact that each of said shoes has an end portion which overlies the joint at the abutting ends of the strip, saidt end portions overlapping one another to protect said oin 7. The light fixture of claim 6, wherein said light source is insertable into the enclosure through said bushmg and comprises:

(A) an elongated tubular holder of substantially stiff but resilient plastic material having one end portion tightly frictionally engaged in the bore of said bushing and its other end adjacent to the center of the enclosure, said holder having (1) a flange on said one end engaging the outer end of the bushing to define the position of the holder with respect to the enclosure, (2) and an internal ledge spaced a distance from said other end of the holder; (B) a metal lamp socket shell tightly frictionally engaged in said other end of the holder and engaged 3,310,671 7 8 with said ledge t0 define the axial position of the References Cited by the Examiner socket With respect to the holder; UNITED STATES PATENTS with said ledge to define the axial position of the 3 135 468 6/1964 Osburn 2402 (C) wire leads connected with the socket shell and extending outwardly through the tubular holder to 5 3246136 4/1966 Cheng 240 8'22 the exterior of the enclosure; FOREIGN PATENTS (D) and an incandescent lamp in said socket. 1,004,817 9/1965 Great Britain 8. The light fixture of claim 7, further characterized I by embossments on said end portion of the holder en- NORTON ANSHER Pnmary Examiner" gaging the wall of the bore in the bushing. 10 W. M. FRYE, Assistant Examiner. 

1. A LIGHT FIXTURE ADAPTED FOR MOUNTING ON ONE SIDE OF A SUPPORTING WALL, AND OF THE TYPE COMPRISING A PAIR OF COAXIAL SPACED APART DISCS, AND A CYLINDRICAL RIM ENCIRCLING THE DISCS AND COACTING THEREWITH TO PROVIDE A DRUM-SHAPED ENCLOSURE FOR A LIGHT SOURCE, AT LEAST ONE OF SAID DISCS BEING A LENS THROUGH WHICH LIGHT CAN PASS, SAID FIXTURE BEING CHARACTERIZED BY THE FOLLOWING: (A) THAT SAID RIM COMPRISES AN ANNULUS OF TOUGH WEATHER-PROOF ELASTIC MATERIAL, HAVING A RADIAL HOLE THERETHROUGH; (B) A PLASTIC MOUNTING SHOE SHAPED TO CONFORM TO THE EXTERIOR OF THE RIM AND SECURED THERETO OVER SAID HOLE; (C) A BOSS INTEGRAL WITH SAID SHOE AND PROJECTING FROM THE EXTERIOR THEREOF, SAID BOSS HAVING A BORE THERETHROUGH COAXIAL WITH SAID HOLE, AND HAVING A NONCIRCULAR COUNTERBORE OPENING TOWARD THE RIM; (D) AND A BUSHING RECEIVED IN SAID BORE, SAID BUSHING HAVING A HEAD NONROTABLY RECEIVED IN SAID COUNTERBORE AND CONTIGUOUS TO THE EXTERIOR OF THE RIM, AND 